GB2542801A - Micro gas sensor with a gas permeable region - Google Patents
Micro gas sensor with a gas permeable region Download PDFInfo
- Publication number
- GB2542801A GB2542801A GB1517238.0A GB201517238A GB2542801A GB 2542801 A GB2542801 A GB 2542801A GB 201517238 A GB201517238 A GB 201517238A GB 2542801 A GB2542801 A GB 2542801A
- Authority
- GB
- United Kingdom
- Prior art keywords
- gas
- membrane
- dielectric
- support structure
- sensing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
- G01N27/128—Microapparatus
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
- G01N27/4148—Integrated circuits therefor, e.g. fabricated by CMOS processing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
- G01N25/22—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on combustion or catalytic oxidation, e.g. of components of gas mixtures
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
- G01N27/16—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by burning or catalytic oxidation of surrounding material to be tested, e.g. of gas
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
- G01N27/4141—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS specially adapted for gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B81—MICROSTRUCTURAL TECHNOLOGY
- B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
- B81B2201/00—Specific applications of microelectromechanical systems
- B81B2201/02—Sensors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/221—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance by investigating the dielectric properties
- G01N2027/222—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance by investigating the dielectric properties for analysing gases
Abstract
A gas sensing device having a dielectric membrane 4, on a semiconductor substrate 1 with a cavity portion; a heater 2, in or on the membrane; a material 6, for sensing a gas, on one side of the membrane; a support structure 7, near the material; and a gas-permeable region 8, coupled to the support to protect the material. The material and support may be on the opposite side of the membrane to the substrate. The material may instead be in the cavity and the substrate may form the support. The gas-permeable region may be a polymer film or comprise a film of metal, dielectric or semiconductor with holes. There may be an electrode 5 under the material, to measure its resistance/capacitance. The material may form or be connected to the gate electrode of a field effect transistor (FET). The material may be a metal oxide or combination of them. There may be a passivation layer over the dielectric membrane. The heater may be a resistive heater comprising a CMOS usable material. Also claimed is a method of manufacture of the device.
Description
Gas sensor with a Gas Permeable Region
Field of the Invention
This invention relates to sensing device having a gas permeable region.
Background of the Invention A gas permeable layer is generally used in a sensing device. Typically, reported devices have a gas permeable layer on package level. US6140144 describes a sensor chip packaged by flip-chip on a ceramic (or similar material) substrate which has a hole through it. For some applications it can have a filter layer/screen in the hole. US8226892 describes a gas sensor based on a FET, which has a gas permeable coating applied directly on the sensing material - this coating also prevents some types of gases from reaching the sensing material US8852513 describes a gas sensor package with two cavities, which are linked. One has the sensor chip, while the other has a filtered window/layer to the outside. EP1775259 describes a package for MEMS - for pressure sensors on a suspended membrane or a buried cavity. The substrate on top has a hole to allow access to outside pressure. US20060001114 describes a chip level package for gas sensors, where the lid is formed by wafer bonding a plastic moulded cap. US20140186999 describes a vacuum package for bolometers using a cavity type lid. US7781250 describes a wafer scale package for MEMS which has a cap substrate with cavity filled with gas. EP2703338 describes a chip in a package, and the package as a gas permeable layer on top. S Kuhne et.al “Wafer-level flame-spray-pyrolysis deposition of gas-sensitive layers on microsensors” Journal of Micromechanics and Microengineering 2008, describes gas sensor with a foil supported on a polyimide structure - however this is to protect the device during wafer dicing, and the foil is removed after dicing. They also mention that a gas permeable film can be used, but not how it would be connected, and show the use of a polyimide layer, but this is not suitable as the distance between the membrane and the gas permeable film is too small and would be affected by the micro-hotplate temperature. S.M. Lee, “Evaluation of the waterproof ability of a hydrophobic nickel micromesh with array type microholes,” describes a wafer proof nickel mesh for use in microphones, but discuss its use as protecting the chip, rather than the mesh being part of the chip. Additionally they do not describe its use in gas sensor.
Summary
Micro-hotplate based resistive gas sensors comprise a thin dielectric membrane with an embedded heater, and a sensing layer (typically a metal oxide) on top of the membrane. The sensing material needs to be protected against liquids and particulate matter which can affect its sensing properties. The packaging of the device needs to be such that it allows air and gas flow to the device, while at the same time, also prevents water, particles and other contaminants from getting to the sensing material.
The invention describes a device that is a micro-hotplate based gas sensor chip with a gas permeable layer deposited or attached on a chip or wafer level to prevent water and dirt from getting to the gas sensing material.
The micro-hotplate gas sensor comprises a heater within the dielectric membrane supported by a semiconductor substrate, and a gas sensitive layer or a catalyst attached to the membrane which can be above or below the membrane. There may or may not be electrodes connected to the sensing material or catalyst to measure its electronic properties.
The gas permeable layer can be a polymer film such as gore-tex. For example, a small support structure can be fabricated on the chip, and the film deposited/attached on top. Alternately, if the sensing material is on the backside of the membrane, the film can be deposited/attached on the backside of the substrate.
The gas permeable layer can also be a film which has a mesh of small holes fabricated that allow air and gas to pass through, but prevent dirt and liquid. This can be attached for example by fabricating and wafer bonding a patterned structure of a metal, semiconductor and/or dielectric onto the chip or wafer.
Alternately, if the gas sensing material or catalyst is on the backside of the membrane, the gas permeable layer can be attached on the backside of the chip to the original semiconductor substrate.
The device can be package in a flip chip, or may have through silicon vias (TSVs) to electrically connect the device. Another packaging method is if the additional semiconductor substrate is smaller than the chip size, allowing the bond pads to be exposed and can be wire bonded.
The invention also describes a method to make such a device - which can be fabricated on a chip level or on a wafer level and then diced into individual chips.
The micro-hotplate may be a CMOS based micro-hotplate. The present invention provides a fully CMOS-compatible or CMOS-based micro-hotplate design based on a closed dielectric membrane structure. Here the dielectric membrane refers to a dielectric membrane in which the dielectric membrane is released by bulk etching of the underlying semiconductor substrate.
The device is preferably fabricated using CMOS-based or CMOS-usable materials. Here the terms “CMOS-based” material or “CMOS-usable” material refer to the materials which are compatible in the state-of-art CMOS processing steps or CMOS process. In this case the heater may be a resistive heater made from CMOS materials such as tungsten, aluminium, titanium, polysilicon, molybdenum or single crystal silicon. The heater may also be a MOSFET heater to allow easier drive control. The dielectric membrane itself may include layers of silicon dioxide and/or silicon nitride as well as spin on glass. The starting wafer may be either bulk silicon, or a silicon on insulator (SOI) wafer. The membrane may be formed by back etching the supporting semiconductor substrate. The membrane cavity may either have near vertical sidewalls (formed by the used of Deep Reactive Ion Etching (DRIE)), or may have sloping sidewalls (formed by the used of anisotropic or crystallographic etching methods such as potassium hydroxide (KOH) or TetraMethyl Ammonium Hydroxide (TMAH)). The use of DRIE allows circular membranes to be made more easily. Such a membrane will typically be a closed membrane structure, supported along its entire perimeter by the substrate. Alternately, the membrane can be formed by a front side etch. In this case the membrane formed is supported by one or more beams which mechanically connects to the substrate. Such a membrane can also be fabricated by a back side etch if the dielectric layers are patterned accordingly.
Alternatively the device may also be fabricated with some or all non-CMOS materials. For example the heater may be fabricated from platinum, or a supporting semiconductor substrate other than silicon may be used.
Aspects and preferred features are set out in the accompanying claims.
We disclose herein a gas sensing device comprising: a dielectric membrane formed on a semiconductor substrate comprising a bulk-etched cavity portion; a heater located within or over the dielectric membrane; a material for sensing a gas which is located on one side of the membrane; a support structure located near the material; and a gas permeable region coupled to the support structure so as to protect the material. It would be appreciated that the term “material” covers both a gas sensing material and a catalytic material which helps to sense a gas.
The gas permeable region may be configured to allow air and gas flow to the device and configured to block liquid and/or particles from getting to the material.
The material may be located on a first side of the dielectric membrane, the first side being an opposite side of the back-etched substrate.
The support structure may be located on the first side of the device and the permeable region is formed on the support structure.
The support structure may be formed surrounding the material.
The material may be located on a second side of the device, the second side being the same side where the back-etched substrate is formed.
The material may be formed in the back-etched cavity of the device.
The semiconductor substrate may form the support structure. The gas permeable region may be coupled with the semiconductor substrate supporting the dielectric membrane.
The membrane may be supported along its entire perimeter by the semiconductor substrate. The gas permeable region may be a polymer film. The polymer film may be polytetrafluoroethylene (PTFE) material, for example GoreTex.
The support structure may be formed on a top-side or back-side of a chip in which the device is included.
The material may be a gas sensing material.
The device may further comprise one or more electrodes underneath or above the gas sensing material.
The electrode may be configured to measure resistance and/or capacitance of the gas sensing material.
The gas sensing material may comprise a metal oxide material or a combination of metal oxides.
The gas sensing material may comprise a metal oxide material selected from a group comprising tin oxide, tungsten oxide, zinc oxide, chromium oxide, or the sensing layer comprises a combination of said metal oxides.
The material may be a catalytic material such as palladium or platinum. In this case the catalytic material, catalyses the combustion of the target gas if present, which increases the temperature of the membrane. This temperature change can be measured to determine the presence and/or concentration of gas.
The material may also form part of a gas FET (Field Effect Transistor) sensing structure. In this case, the material is present on the gate of the FET, or an electrode underneath the material is connected to the gate of the FET. Presence of gas alters the work function of the FET.
The dielectric membrane may be formed using an etching technique for bulk-etching the substrate, the etching technique being selected from a group comprising deep reactive ion etching (DRIE), anisotropic or crystallographic wet etching, potassium hydroxide (KOH) and tetramethyl ammonium hydroxide (TMAH).
The dielectric membrane may comprise: a membrane cavity comprising vertical side walls or sloping side walls, or a cavity formed by a front side etch that does not extend all the way through the substrate; one or more dielectric layers comprising silicon dioxide and/or silicon nitride; one or more layers of spin on glass, and a passivation layer over the one or more dielectric layers.
The material for sensing a gas may be formed on the passivation layer of the dielectric membrane or in the membrane cavity of the device.
The heater may be a resistive heater comprising a CMOS usable material comprising aluminium, copper, titanium, molybdenum, polysilicon, single crystal silicon tungsten, or titanium nitride. The heater can also be a MOSFET.
The device may be a CMOS based micro-hotplate in which the heater comprises a CMOS interconnect metal, and the dielectric membrane comprises CMOS dielectric layers.
The device may also be made with non-CMOS materials, for example using platinum as a heater.
The semiconductor substrate may be a bulk silicon substrate or an SOI substrate.
The device may be packaged in a flip chip on a printed circuit board (PCB). The device may comprise through silicon vias (TSVs).
The support structure may cover the dielectric membrane area, leaving a bond pad area open to allow wire bonding.
An array of gas sensing devices incorporating a gas sensing device as described above, wherein the array of gas sensing devices may be arranged on the same chip.
Each sensing device may comprise a separate gas permeable region.
The sensing devices may comprise a common gas permeable region.
We disclose herein a method of manufacturing a gas sensing device, the method comprising: forming a dielectric membrane formed on a semiconductor substrate comprising a back-etched cavity portion; forming a heater within or over the dielectric membrane; forming a material for sensing a gas on one side of the membrane; forming a support structure near the material; and forming an gas permeable region coupled to the support structure so as to protect the material.
The step of forming the dielectric membrane may comprise forming the dielectric membrane such that it is supported along its entire perimeter by the semiconductor substrate.
The step of forming the dielectric membrane comprises using an etching technique to back-etch the semiconductor substrate to form the back-etched portion.
The etching technique may be selected from a group comprising deep reactive ion etching (DRIE), anisotropic or crystallographic wet etching, potassium hydroxide (KOH) and tetramethyl ammonium hydroxide (TMAH).
Brief Description of the Preferred Embodiments
Some preferred embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:
Figure 1 shows a gas sensor with a gas permeable layer;
Figure 2 shows an alternative gas sensor in which through silicon vias (TSVs) are used;
Figure 3 shows an alternative gas sensor;
Figure 4 shows an alternative gas sensor in which the gas permeable layer has holes; Figure 5 shows an alternative gas sensor in which the sensing material is below the membrane, and the gas permeable layer is on the back side, supported by the silicon substrate itself,
Figure 6 shows an alternative gas sensor which is bonded by a flip chip; and
Figure 7 shows an alternative gas sensor where the membrane is formed by a front side etch
Detailed Description of the Preferred Embodiments
Figure 1 shows a gas sensor with a sensing material 6, a silicon substrate 1 with a gas permeable layer 8 attached on top. The heater 2 and heater tracks or metallization 3 are embedded within the dielectric membrane 4 supported on the substrate 1. Electrodes 5 on top of the membrane connect to a sensing material 6 which has been grown or deposited on the membrane. An additional patterned semiconductor 7 (or the support structure) is attached at the top by wafer bonding and the gas permeable layer 8 is on top of this support structure 7. The dielectric membrane 4 and the passivation can include one or more combinations of silicon dioxide and silicon nitride, or other dielectric layers. In one example, the gas permeable layer or region is a metal, dielectric and/or semiconductor layer with multiple holes. This can be formed for example, by depositing a dielectric or metal layer on a substrate. Then making holes within the metal or dielectric layer. And then back etching a selected part of the substrate and joining this structure to the gas sensing hotplate by wafer bonding.
Figure 2 shows an alternative gas sensor in which through silicon vias (TSVs) 9 are used to connect electrically to the device. The TSVs are generally connected to metallization or pads (not shown). The remaining features of the gas sensor are the same as those described in respect of Figure 1 above and thus carry the same reference numbers.
Figure 3 shows an alternative gas sensor in which the support structure 7 (or the additional semiconductor substrate) is smaller, so that the bond pads 11 are exposed and can be electrically connected by wire bonding to either a package or a printed circuit board (not shown in the figure). Furthermore, this figure also shows a passivation layer 10 - which may or may not be present on the device. The remaining features of the gas sensor are the same as those described in respect of Figures 1 and 2 above and thus carry the same reference numbers.
Figure 4 shows an alternative gas sensor in which the gas permeable layer 8 has holes, or is gas permeable even in regions which connect to the semiconductor support structure 7. The gas permeable layer can be for example a film such as gore-tex. It can also be a film of metal, dielectric and/or semiconductor with holes. The remaining features of the gas sensor are the same as those described in respect of Figures 1 to 3 above and thus carry the same reference numbers.
Figure 5 shows an alternative gas sensor in which the sensing material 6 is below the dielectric membrane 4, and the gas permeable layer 8 is on the back side, supported by the silicon back-etched substrate 1 itself. In this example, no additional support structure is needed as the back-etched substrate 1 acts as the support structure. The remaining features of the gas sensor are the same as those described in respect of Figures 1 to 4 above and thus carry the same reference numbers.
Figure 6 shows an alternative gas sensor with the sensing material 6 below the dielectric membrane 4, and a gas permeable layer 5 on the backside, bonded by flip chip with the bonds 13 connected to a printed circuit board (PCB) 12. The bond 13 can be generally connected to metallization or pads (not shown). In this example the chip is bonded on the front or top side of the chip. The remaining features of the gas sensor are the same as those described in respect of Figures 1 to 5 above and thus carry the same reference numbers.
Figure 7 shows an alternative gas sensor, where the membrane 14 is a suspended membrane, formed by a front side etching of the substrate, and is supported by one or more beams (not shown). The membrane 14 includes dielectric material, for example, silicon oxide. The substrate 1 includes a triangle region 10 which is generally empty and is formed due to the front-side etching of the substrate. The remaining features of Figure 7 are the same as those described above and thus carry the same reference numbers.
In the above mentioned embodiments, a gas sensing material 6 is disposed on an electrode 5. The electrode 5 is configured to measure resistance and/or capacitance of the gas sensing material 6. In an alternative embodiment, a catalytic material can be used instead of the gas sensing material. When the catalytic material is used, no electrode underneath it is generally necessary, since the detection is done by measuring the change in temperature of the membrane rather than the resistance or capacitance of the material. Alternately, the gas sensing material could be deposited as part of a gate, or an extended gate of a gas sensing FET.
In summary, the present invention provides a micro-hotplate based gas sensor chip that attaches the gas permeable layer onto the chip itself. The prior art reports typically have the gas permeable layer on the package, whereas the present invention provides the gas permeable layer in the chip level. The prior art devices are not for a membrane based device, whereas the present invention uses membrane based devices. The prior art devices generally have relatively larger holes for the purpose of allowing air flow, but do not stop water or particles. The prior art devices generally have a single hole (for example EP1775259). Alternately, the method of the present invention can allow a smaller package (or even a chip level package), easier handling during assembly, and lower cost. Furthermore, in the prior art device, the gas permeable layer can be formed on the sensing material itself which can affect the properties of the sensing material. This problem does not exist in the present invention as there is a support structure provided to create a gap between the sensing material and the gas permeable layer. Further, in some prior art devices, a plastic moulded cap is provided on which it is difficult to have the gas permeable layer. This problem does not exist in the present invention.
Although the invention has been described in terms of preferred embodiments as set forth above, it should be understood that these embodiments are illustrative only and that the claims are not limited to those embodiments. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims. Each feature disclosed or illustrated in the present specification may be incorporated in the invention, whether alone or in any appropriate combination with any other feature disclosed or illustrated herein.
Claims (42)
1. A gas sensing device comprising: a dielectric membrane formed on a semiconductor substrate comprising a bulk-etched cavity portion; a heater located within or over the dielectric membrane; a material for sensing a gas, wherein the material is located on one side of the membrane; a support structure located near the material; and a gas permeable region coupled to the support structure so as to protect the material.
2. A device according to claim 1, wherein the gas permeable region is configured to allow air and gas flow to the device and configured to block liquid and/or particles from getting to the material.
3. A device according to claim 1 or 2, wherein the material is located on a first side of the dielectric membrane, the first side being an opposite side of the bulk-etched substrate.
4. A device according claim 3, wherein the support structure is located on the first side of the device and the permeable region is formed on the support structure.
5. A device according claim 3 or 4, wherein the support structure is formed surrounding the material.
6. A device according to claim 1 or 2, wherein the material is located on a second side of the device, the second side being the same side where the bulk-etched substrate is formed.
7. A device according to claim 6, wherein the material is formed in the back-etched cavity of the device.
8. A device according to claim 6 or 7, wherein the semiconductor substrate forms the support structure.
9. A device according to claim 6, 7 or 8, wherein the gas permeable region is coupled with the semiconductor substrate supporting the dielectric membrane.
10. A device according to any preceding claim, wherein the membrane is supported along its entire perimeter by the semiconductor substrate.
11. A device according to any of the claims 1 to 9 wherein the membrane is only supported by one or more dielectric beams to connect the membrane to the substrate.
12. A device according to any preceding claim, wherein the gas permeable region is a polymer film.
13. A device according to claim 12, wherein the polymer film is gore-tex.
14. A device according to any of the claims 1 toll, wherein the gas permeable region comprises a film of metal, dielectric or semiconductor with several holes.
15. A device according to any preceding claim, wherein the support structure is formed on a top-side or back-side of a chip in which the device is included.
16. A device according to any preceding claim, wherein the material is a gas sensing material.
17. A device according to claim 16, further comprising an electrode underneath the gas sensing material.
18. A device according to claim 17, wherein the electrode is configured to measure resistance and/or capacitance of the gas sensing material.
19. A device according to any one of claims 16 to 18, wherein the gas sensing material comprises a metal oxide material or a combination of metal oxides.
20. A device according to claim 19, wherein the gas sensing material comprises a metal oxide material selected from a group comprising tin oxide, tungsten oxide, zinc oxide, chromium oxide, or the sensing layer comprises a combination of said metal oxides.
21. A device according to any one of claims 1 to 15, wherein the material is a catalytic material.
22. A device according to any one of claims 1 to 15, wherein the material is deposited as a gate electrode, or is electrically connected to the gate electrode of a field effect transistor (FET).
23. A device according to any preceding claim, wherein the dielectric membrane is formed using an etching technique for back-etching the substrate, the etching technique being selected from a group comprising deep reactive ion etching (DRIE), anisotropic or crystallographic wet etching, potassium hydroxide (KOH) and tetramethyl ammonium hydroxide (TMAH).
24. A device according to any one of claims 1 to 22, wherein the dielectric membrane is formed by a front side etch of the substrate.
25. A device according to any preceding claim, wherein the dielectric membrane comprises: a membrane cavity comprising vertical side walls or sloping side walls or a cavity formed by a front side etch that does not extend all the way through the substrate; one or more dielectric layers comprising silicon dioxide and/or silicon nitride; one or more layers of spin on glass, and a passivation layer over the one or more dielectric layers.
26. A device according to claim 25, wherein the material for sensing a gas is formed on the passivation layer of the dielectric membrane or in the membrane cavity of the device.
27. A device according to any preceding claim, wherein the heater is a resistive heater comprising a CMOS usable material comprising aluminium, copper, titanium, molybdenum, polysilicon, single crystal silicon tungsten, or titanium nitride.
28. A device according to any preceding claim, wherein the device is a CMOS based micro-hotplate in which the heater comprises a CMOS interconnect metal, and the dielectric membrane comprises CMOS dielectric layers.
29. A device according to any preceding claim, wherein the semiconductor substrate is a bulk silicon substrate or an SOI substrate.
30. A device according to any preceding claim, wherein the device is packaged in a flip chip on a printed circuit board (PCB).
31. A device according to any preceding claim, wherein the device comprises through silicon vias (TSVs).
32. A device according to any preceding claim, wherein the support structure covers the dielectric membrane area, leaving a bond pad area open to allow wire bonding.
33. An array of gas sensing devices incorporating a gas sensing device according to any preceding claim, wherein the array of gas sensing devices are arranged on the same chip.
34. An array according to claim 33, wherein each sensing device comprises a separate gas permeable region.
35. An array according to claim 33, wherein the sensing devices comprise a common gas permeable region.
36. A method of manufacturing a gas sensing device, the method comprising: forming a dielectric membrane formed on a semiconductor substrate comprising a bulk-etched cavity portion; forming a heater within or over the dielectric membrane; forming a material for sensing a gas on one side of the membrane; forming a support structure near the material; and forming a gas permeable region coupled to the support structure so as to protect the material.
37. A method according to claim 36 wherein the support structure is attached by wafer bonding.
38. A method according to claim 36 or 37 wherein the gas permeable layer is attached to the support structure, before the support structure is attached to the gas sensing device.
39. A method according to claim 36, 37 or 38, wherein forming the dielectric membrane comprises forming the dielectric membrane such that it is supported along its entire perimeter by the semiconductor substrate.
40. A method according to any one of claims 36 to 39, wherein forming the dielectric membrane comprises using an etching technique to back-etch the semiconductor substrate to form the back-etched portion.
41. A method according to claim 40, wherein the etching technique is selected from a group comprising deep reactive ion etching (DRIE), anisotropic or crystallographic wet etching, potassium hydroxide (KOH) and tetramethyl ammonium hydroxide (TMAH).
42. A gas sensing device and a method of manufacturing a gas sensing device, as hereinbefore described with reference to and as illustrated in the accompanying drawings.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1517238.0A GB2542801A (en) | 2015-09-30 | 2015-09-30 | Micro gas sensor with a gas permeable region |
| US15/763,294 US11022576B2 (en) | 2015-09-30 | 2016-09-19 | Gas sensor with a gas permeable region |
| EP16770344.6A EP3356811A1 (en) | 2015-09-30 | 2016-09-19 | Gas sensor with a gas permeable region |
| CN201680059137.1A CN108369208A (en) | 2015-09-30 | 2016-09-19 | Gas sensor with gas-permeable region |
| PCT/GB2016/052921 WO2017055806A1 (en) | 2015-09-30 | 2016-09-19 | Gas sensor with a gas permeable region |
| US17/244,623 US20210247345A1 (en) | 2015-09-30 | 2021-04-29 | Gas Sensor with a Gas Permeable Region |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1517238.0A GB2542801A (en) | 2015-09-30 | 2015-09-30 | Micro gas sensor with a gas permeable region |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201517238D0 GB201517238D0 (en) | 2015-11-11 |
| GB2542801A true GB2542801A (en) | 2017-04-05 |
Family
ID=54544304
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1517238.0A Withdrawn GB2542801A (en) | 2015-09-30 | 2015-09-30 | Micro gas sensor with a gas permeable region |
Country Status (5)
| Country | Link |
|---|---|
| US (2) | US11022576B2 (en) |
| EP (1) | EP3356811A1 (en) |
| CN (1) | CN108369208A (en) |
| GB (1) | GB2542801A (en) |
| WO (1) | WO2017055806A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102018207548B3 (en) | 2018-05-16 | 2019-06-19 | Robert Bosch Gmbh | Sensor device with a hydrophobic and / or anti-adhesive protective layer and method for producing such a sensor device |
| WO2019122888A1 (en) * | 2017-12-22 | 2019-06-27 | Ams Sensors Uk Limited | An infra-red device |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2542801A (en) | 2015-09-30 | 2017-04-05 | Cambridge Cmos Sensors Ltd | Micro gas sensor with a gas permeable region |
| CN108088877B (en) * | 2017-12-25 | 2020-05-01 | 江西省吉晶微电子有限公司 | Multifunctional semiconductor device |
| CN107960008B (en) * | 2017-12-25 | 2020-06-12 | 浙江常山聚华电子有限公司 | Integrated circuit board |
| US20200096396A1 (en) * | 2018-09-26 | 2020-03-26 | Ams Sensors Uk Limited | Gas Sensors |
| EP4012383B1 (en) | 2018-10-30 | 2023-12-20 | Sciosense B.V. | Electro-thermal based device and method for operating a heater |
| US11674916B2 (en) * | 2018-11-12 | 2023-06-13 | Sciosense B.V. | Gas sensor |
| TWI717178B (en) * | 2019-12-30 | 2021-01-21 | 財團法人工業技術研究院 | A microelectromechanical apparatus having hermitic chamber |
| DE102020100244A1 (en) | 2020-01-08 | 2021-07-08 | X-FAB Global Services GmbH | Method for producing a membrane component and a membrane component |
| DE102020110790B4 (en) * | 2020-04-21 | 2022-01-05 | Infineon Technologies Ag | Sensor devices with gas-permeable lids and associated manufacturing processes |
| CN112730537A (en) * | 2020-12-22 | 2021-04-30 | 杭州未名信科科技有限公司 | Capacitance type hydrogen sensor and preparation method thereof |
| CN112730529A (en) * | 2020-12-22 | 2021-04-30 | 杭州未名信科科技有限公司 | Resistance type hydrogen sensor and preparation method thereof |
| TWI808541B (en) * | 2021-11-22 | 2023-07-11 | 財團法人工業技術研究院 | Breathable lid of chip package structure and manufacturing method thereof |
| SE545446C2 (en) * | 2021-12-22 | 2023-09-12 | Senseair Ab | Capped semiconductor based sensor and method for its fabrication |
| CN115655393B (en) * | 2022-11-09 | 2023-05-16 | 湖南大学 | MEMS airflow sensor |
| CN116854023B (en) * | 2023-09-05 | 2023-12-05 | 北京六知科技有限公司 | MEMS semiconductor chip and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090246084A1 (en) * | 2008-03-26 | 2009-10-01 | Micronas Gmbh | Gas Sensor |
| GB2523788A (en) * | 2014-03-05 | 2015-09-09 | Cambridge Cmos Sensors Ltd | CMOS-Based semiconductor device on micro-hotplate and method of fabrication |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5747808A (en) * | 1994-02-14 | 1998-05-05 | Engelhard Sensor Technologies | NDIR gas sensor |
| US6140144A (en) | 1996-08-08 | 2000-10-31 | Integrated Sensing Systems, Inc. | Method for packaging microsensors |
| DE10204458A1 (en) * | 2002-02-05 | 2003-08-14 | Stefan Raible | gas sensor |
| US7296458B2 (en) * | 2002-10-17 | 2007-11-20 | Advanced Technology Materials, Inc | Nickel-coated free-standing silicon carbide structure for sensing fluoro or halogen species in semiconductor processing systems, and processes of making and using same |
| TWI236111B (en) | 2004-06-30 | 2005-07-11 | Ind Tech Res Inst | Apparatus and method for wafer level packaging |
| JP4115482B2 (en) * | 2005-02-22 | 2008-07-09 | 日本特殊陶業株式会社 | Gas sensor |
| GB0517869D0 (en) * | 2005-09-02 | 2005-10-12 | Univ Warwick | Gas-sensing semiconductor devices |
| EP1775259A1 (en) | 2005-10-14 | 2007-04-18 | STMicroelectronics S.r.l. | Wafer level package for sensor devices |
| DE102006060113A1 (en) * | 2006-12-20 | 2008-06-26 | Appliedsensor Gmbh | Sensor and manufacturing process of a sensor |
| CN101123231B (en) | 2007-08-31 | 2010-11-03 | 晶方半导体科技（苏州）有限公司 | Encapsulation structure for wafer chip dimension of micro mechanical-electrical system and its making method |
| US7878056B2 (en) * | 2007-12-19 | 2011-02-01 | Siargo Ltd. | Micromachined thermal mass flow sensor with self-cleaning capability and methods of making the same |
| DE102008042139A1 (en) * | 2008-09-16 | 2010-03-18 | Robert Bosch Gmbh | Exhaust gas protective layers for high temperature ChemFET exhaust gas sensors |
| DE102010042108B4 (en) * | 2010-01-18 | 2013-10-17 | Heimann Sensor Gmbh | Thermopile infrared sensor in monolithic Si micromechanics |
| US8410560B2 (en) * | 2010-01-21 | 2013-04-02 | Cambridge Cmos Sensors Ltd. | Electromigration reduction in micro-hotplates |
| EP2533037B1 (en) | 2011-06-08 | 2019-05-29 | Alpha M.O.S. | Chemoresistor type gas sensor having a multi-storey architecture |
| US8852513B1 (en) | 2011-09-30 | 2014-10-07 | Silicon Laboratories Inc. | Systems and methods for packaging integrated circuit gas sensor systems |
| ITTO20120753A1 (en) * | 2012-08-30 | 2014-03-01 | St Microelectronics Srl | ENCAPSULATED DEVICE EXPOSED TO AIR, ENVIRONMENT AND LIQUIDS AND RELATIVE PROCESS OF MANUFACTURE |
| EP2939265B1 (en) | 2012-12-31 | 2018-10-31 | Flir Systems, Inc. | Wafer level packaging of microbolometer vacuum package assemblies |
| EP2762864B1 (en) * | 2013-01-31 | 2018-08-08 | Sensirion AG | Membrane-based sensor device and method for manufacturing the same |
| JP6440727B2 (en) * | 2013-11-12 | 2018-12-19 | エルファウンドリー エッセ エッレ エッレ | Integrated gas sensor and related manufacturing method |
| GB2542801A (en) | 2015-09-30 | 2017-04-05 | Cambridge Cmos Sensors Ltd | Micro gas sensor with a gas permeable region |
-
2015
- 2015-09-30 GB GB1517238.0A patent/GB2542801A/en not_active Withdrawn
-
2016
- 2016-09-19 CN CN201680059137.1A patent/CN108369208A/en active Pending
- 2016-09-19 EP EP16770344.6A patent/EP3356811A1/en active Pending
- 2016-09-19 US US15/763,294 patent/US11022576B2/en active Active
- 2016-09-19 WO PCT/GB2016/052921 patent/WO2017055806A1/en active Application Filing
-
2021
- 2021-04-29 US US17/244,623 patent/US20210247345A1/en not_active Abandoned
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090246084A1 (en) * | 2008-03-26 | 2009-10-01 | Micronas Gmbh | Gas Sensor |
| GB2523788A (en) * | 2014-03-05 | 2015-09-09 | Cambridge Cmos Sensors Ltd | CMOS-Based semiconductor device on micro-hotplate and method of fabrication |
Non-Patent Citations (1)
| Title |
|---|
| Journal of Micromechanics and Microengineering, Vol. 18, No. 3, 2008, S. Kuhne et.al, "Wafer-level flame-spray-pyrolysis deposition of gas-sensitive layers on microsensors", 035040 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019122888A1 (en) * | 2017-12-22 | 2019-06-27 | Ams Sensors Uk Limited | An infra-red device |
| US10636777B2 (en) | 2017-12-22 | 2020-04-28 | Ams Sensors Uk Limited | Infra-red device |
| CN111556958A (en) * | 2017-12-22 | 2020-08-18 | Ams传感器英国有限公司 | Infrared device |
| DE102018207548B3 (en) | 2018-05-16 | 2019-06-19 | Robert Bosch Gmbh | Sensor device with a hydrophobic and / or anti-adhesive protective layer and method for producing such a sensor device |
Also Published As
| Publication number | Publication date |
|---|---|
| US20180202958A1 (en) | 2018-07-19 |
| GB201517238D0 (en) | 2015-11-11 |
| US20210247345A1 (en) | 2021-08-12 |
| WO2017055806A1 (en) | 2017-04-06 |
| EP3356811A1 (en) | 2018-08-08 |
| US11022576B2 (en) | 2021-06-01 |
| CN108369208A (en) | 2018-08-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20210247345A1 (en) | Gas Sensor with a Gas Permeable Region | |
| EP2912426B1 (en) | Combined pressure and humidity sensor | |
| EP1096259B1 (en) | High-vacuum packaged microgyroscope and method for manufacturing the same | |
| KR101970229B1 (en) | Capacitive sensor integrated onto semiconductor circuit | |
| US9926188B2 (en) | Sensor unit including a decoupling structure and manufacturing method therefor | |
| EP2481703B1 (en) | Sensor protection | |
| TWI657998B (en) | Micro-electromechanical component and process for the production of micro-electromechanical components | |
| TWI589879B (en) | Mikromechanischer inertialsensor und verfahren zu dessen herestellung | |
| JP6713259B2 (en) | Sensor chip | |
| EP3206027B1 (en) | Sensor chip comprising electrostatic discharge protection element | |
| CN107265395A (en) | Method and corresponding MEMS pressure sensor for manufacturing MEMS pressure sensor | |
| JP2008517288A (en) | Method for mounting a semiconductor chip and corresponding semiconductor chip device | |
| KR20160088111A (en) | Complex sensor, package having the same and manufacturing method thereof | |
| CN110655033A (en) | Improved stress decoupling MEMS sensor | |
| US10858245B2 (en) | Deposition of protective material at wafer level in front end for early stage particle and moisture protection | |
| JP2008089421A (en) | Pressure sensor package | |
| US8887563B2 (en) | Transducer and method for manufacturing same | |
| JP7252048B2 (en) | SENSOR DEVICE AND SENSOR DEVICE MANUFACTURING METHOD | |
| US20200150069A1 (en) | Gas sensor | |
| KR20190116371A (en) | Micromechanical sensor device with integrated housing seal, micromechanical sensor assembly, and corresponding manufacturing method | |
| Li et al. | Selective Encapsulation Using a Polymeric or Bonded Silicon Constraint Dam for Media Compatible Pressure Sensor Applications | |
| JP2009294152A (en) | Capacity sensor package |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) |
Free format text: REGISTERED BETWEEN 20210107 AND 20210113 |
|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |